<?php //$Id: text.php,v 1.1.2.2 2007/12/11 13:01:13 nfreear Exp $

require_once($CFG->dirroot.'/user/filters/lib.php');

/**
 * Generic filter for text fields.
 */
class user_filter_text extends user_filter_type {
	var $_field;

	/**
	 * Constructor
	 * @param string $name the name of the filter instance
	 * @param string $label the label of the filter instance
	 * @param boolean $advanced advanced form element flag
	 * @param string $field user table filed name
	 */
	function user_filter_text($name, $label, $advanced, $field) {
		parent::user_filter_type($name, $label, $advanced);
		$this->_field = $field;
	}

	/**
	 * Returns an array of comparison operators
	 * @return array of comparison operators
	 */
	function getOperators() {
		return array(0 => get_string('contains', 'filters'),
					 1 => get_string('doesnotcontain','filters'),
					 2 => get_string('isequalto','filters'),
					 3 => get_string('startswith','filters'),
					 4 => get_string('endswith','filters'),
					 5 => get_string('isempty','filters'));
	}

	/**
	 * Adds controls specific to this filter in the form.
	 * @param object $mform a MoodleForm object to setup
	 */
	function setupForm(&$mform) {
		$objs = array();
		$objs[] =& $mform->createElement('select', $this->_name.'_op', null, $this->getOperators());
		$objs[] =& $mform->createElement('text', $this->_name, null);
		$grp =& $mform->addElement('group', $this->_name.'_grp', $this->_label, $objs, '', false);
		$grp->setHelpButton(array('text',$this->_label,'filters'));
		$mform->disabledIf($this->_name, $this->_name.'_op', 'eq', 5);
		if ($this->_advanced) {
			$mform->setAdvanced($this->_name.'_grp');
		}
	}

	/**
	 * Retrieves data from the form data
	 * @param object $formdata data submited with the form
	 * @return mixed array filter data or false when filter not set
	 */
	function check_data($formdata) {
		$field	= $this->_name;
		$operator = $field.'_op';

		if (array_key_exists($operator, $formdata)) {
			if ($formdata->$operator != 5 and $formdata->$field == '') {
				// no data - no change except for empty filter
				return false;
			}
			return array('operator'=>(int)$formdata->$operator, 'value'=>$formdata->$field);
		}

		return false;
	}

	/**
	 * Returns the condition to be used with SQL where
	 * @param array $data filter settings
	 * @return string the filtering condition or null if the filter is disabled
	 */
	function get_sql_filter($data) {
		$operator = $data['operator'];
		$value	= addslashes($data['value']);
		$field	= $this->_field;

		if ($operator != 5 and $value === '') {
			return '';
		}

		$ilike = sql_ilike();

		switch($operator) {
			case 0: // contains
				$res = "$ilike '%$value%'"; break;
			case 1: // does not contain
				$res = "NOT $ilike '%$value%'"; break;
			case 2: // equal to
				$res = "$ilike '$value'"; break;
			case 3: // starts with
				$res = "$ilike '$value%'"; break;
			case 4: // ends with
				$res = "$ilike '%$value'"; break;
			case 5: // empty
				$res = "=''"; break;
			default:
				return '';
		}
		return $field.' '.$res;
	}

	/**
	 * Returns a human friendly description of the filter used as label.
	 * @param array $data filter settings
	 * @return string active filter label
	 */
	function get_label($data) {
		$operator  = $data['operator'];
		$value	 = $data['value'];
		$operators = $this->getOperators();

		$a = new object();
		$a->label	= $this->_label;
		$a->value	= '"'.s($value).'"';
		$a->operator = $operators[$operator];


		switch ($operator) {
			case 0: // contains
			case 1: // doesn't contain
			case 2: // equal to
			case 3: // starts with
			case 4: // ends with
				return get_string('textlabel', 'filters', $a);
			case 5: // empty
				return get_string('textlabelnovalue', 'filters', $a);
		}

		return '';
	}
}
